33 kV Gas Insulated Switchgear Part 1

Posted on Leave a commentPosted in Electrical, Study Material

33 kV Gas Insulated Switchgear In Underground metro stations, there are two 33 kV auxiliary substations in each station. These substations have GIS type switchgear installation, separate earth mats and METs, a switching room or feeder post for ROCS charging.   I tried to keep a short, crisp summary of a typical 33 kV GIS switchgear which might help in working in a 33kV substation.   The insulating gas for this switchgear would  be SF6 Sulphur Hexafluoride, at a temperature 20 °C at 0.05 MPa. Bus Rating would be 33 kV GIS, 25 kA for 3 sec, Single bus bar […]

How to calculate size of a cable for 11kV or 33kV line

Posted on 5 CommentsPosted in Electrical, Study Material

There are three factors affecting the size of a cable Load Length & Voltage drop Short Circuit Current of the system Now, we can consider these four points one by one and choose a cable which complies all these requirements. Load – The load of circuit is available in kW or watts. For example if you are calculating the size of cable for a 1 kW single phase pump. Load on the circuit is 1 kW. Now, calculate the current that will be running in the circuit due to 1 kW load of the pump. P=Volt X Current X Cos […]